A highly efficient surface plasmon resonance(SPR)-based DNA assay is developed

by employing noncovalently functionalized graphene nanosheets as the substrate

and enzymatic catalysis-induced polymerization as the mass relay.The objective of this strategy was manifold:first of all

to sensitize the overall SPR output by in situ optimized electrogeneration of graphene thin-film

that was characterized by atomic force micro-topography; secondly

to regulate the self-assembly and orientation of biotinylated capture probes on nickel-chelated nitrilotriacetic acid scaffolds

which were anchored onto graphene-supported pyrenyl derivatives; and lastly

to synergize the signal amplification via real-time conversion of the additive aniline into polyaniline precipitation by horseradish peroxidase-tagged reporters. With this setup

a precise and replicable DNA sensing platform for specific targets was achieved with a detection limit down to femtomolar

demonstrating a beneficial exploration and exploitation of two-dimensional nanomaterials as unique SPR infrastructure.The possibility of such “bottom-up” architecture mounted with “top-down” weight reactor would be most likely extensible and adaptable to protein determinations.